1. Field of the Invention
The present invention relates, in general, to a transmitting and receiving antenna for animal training devices and, more particularly, to a transmitting and receiving antenna attached to a transceiver for animal training devices and used for transmitting and receiving signals of a specific frequency band.
2. Description of the Prior Art
A conventional transmitting and receiving antenna, which is usable with animal training devices, is shown in FIG. 1. As shown in the drawing, the conventional antenna for animal training devices comprises a stud bolt 7, which consists of a hexagonal body 1, an externally-threaded connector 3 and a support projection rod 5. The hexagonal body 1 has a hexagonal cross-section, with the externally-threaded connector 3 extending from one end of the body 1 and the support projection rod 5 extending from the other end of the body 1. A flexible coil spring 9 is fitted over the stud bolt 7 and is fixed to the bolt 7 through a soldering process. A longitudinal rod 11, made of glass fiber, is inserted into the outside end of the coil spring 9. A loading coil 13 is fixed to the coil spring 9 at one end thereof through a soldering process and is coiled around the longitudinal rod 11. The antenna also has a protection cover 15, which is assembled with the hexagonal body 1 of the stud bolt 7 so as to cover both the coil spring 9 and the loading coil 13 wound around the longitudinal rod 11. This protection cover 15 thus protects both the coil spring 9 and the loading coil 13.
In such a conventional transmitting and receiving antenna, it is necessary to use a flexible coil spring 9, which is formed by regularly coiling a copper-plated flexible steel wire at a predetermined pitch, so as to allow the antenna to elastically maintain its desired straight shape while being free from being cut or bent when the antenna is unconsciously caught by an obstacle. Due to such a flexible coil spring 9, it is impossible to reduce the length of the antenna to a desired short length. This finally forces the antenna to have such an awkward length that the antenna is inconvenient to a user while carrying or using it.
In addition, it is necessary to cut a length of the distal end of the loading coil 13, wound around the longitudinal rod 11 made of glass fiber, in order to set a specific frequency band and to allow the antenna to transmit and receive signals of such specific frequency band. It is thus very difficult to precisely or finely control the frequency band of signals to be transmitted and received by the antenna. When an exceeding length of the loading coil 13 is unconsciously cut while setting a specific frequency band of signals to be transmitted and received by the antenna, it is impossible for a resulting antenna to transmit or receive signals of the specific frequency band. This finally reduces the operational reliability of such antennae.